#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
// The pins for I2C are defined by the Wire-library.
// On an arduino UNO:       A4(SDA), A5(SCL)
// On an arduino MEGA 2560: 20(SDA), 21(SCL)
// On an arduino LEONARDO:   2(SDA),  3(SCL), ...
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

int input_power = A0;
float volgate = 0.0;
long unsigned last_time1 = 0; //串口输出
long unsigned last_time2 = 0; //oled输出
void setup() {
  Serial.begin(9600);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }

  // Show initial display buffer contents on the screen --
  // the library initializes this with an Adafruit splash screen.
  display.display();
  delay(1000); // Pause for 2 seconds

  // Clear the buffer
  display.clearDisplay();
}

void show_s(void) {
  display.clearDisplay();
  display.setTextSize(2);             // Normal 1:1 pixel scale
  display.setTextColor(SSD1306_WHITE);        // Draw white text
  display.setCursor(0, 0);            // Start at top-left corner
  display.println(F("Volgate"));
  display.print(volgate); display.println("V");
  display.display();
}

void loop() {
  volgate = analogRead(input_power);
  volgate = volgate*0.00672;//这个后面的数字需要根据实际计算修改
  if (millis() - last_time1 > 1000) {
    Serial.println(volgate);
    last_time1 = millis();
  }

  if (millis() - last_time2 > 200) {
    show_s();
    last_time2 = millis();
  }
  delay(10);

}
